Add NFS spidering module to enumerate readable files

[sheikhshaheerimran]

Adds NFS spider functionality to recursively enumerate NFS shares and identify readable/downloadable files.

• Uses ACCESS3_READ permission checks to verify actual accessibility
• Supports root escape technique for full filesystem traversal
• Pattern and regex filtering for targeted searches

Closes #1023

Usage:

# Spider using root escape
nxc nfs <target> --spider

# Spider specific path with depth limit
nxc nfs <target> --spider /home --depth 3

# Spider specific share
nxc nfs <target> --share /exports --spider

Type of change

• New feature

Setup guide for the review

Test environment:

• Linux with Python 3.10+
• Target: Any NFS server with exported shares

To test:

1. Set up an NFS server with exported shares
2. Run nxc nfs --spider to enumerate readable files
3. Verify results by attempting to download or mount manually

Screenshots (if appropriate):

Checklist:

• I have ran Ruff against my changes
• I have added or updated the tests/e2e_commands.txt file
• New and existing e2e tests pass locally with my changes
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas

[termanix]

Good job! Can you also share some example screenshots?

[NeffIsBack]

Yes, thanks for the PR! But please use the PR template.

[sheikhshaheerimran]

@NeffIsBack i have updated PR. Apologies for missing template. Can you review and guide if any further changes are required?

[NeffIsBack]

@NeffIsBack i have updated PR. Apologies for missing template. Can you review and guide if any further changes are required?

No worries, we'll work with what we've got. I don't have much time at the moment and there are a lot of other PRs that i have to review first, but eventually i will get to it.